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Fluid Journal : Winter 2015
4 The Fluid Journal Winter 2015 Timing, concentrations, and placement in use of fluid fertilizers stressed. Summary: Yield improvements were impressive with 6-24-6, providing over a 3 ton (@65 percent moisture) improvement over the grower standard practice of 20.5 tons, compared to 23.3. Improvements with these types of applications for both years have encouraged the Cooperating Farm Managers to incorporate these applications into many of the alfalfa fields for the future. Improvements of yields were impressive with both 3-18-18 and 6-24-6. Yields Improve In Irrigated Alfalfa Using NPK Fluids The Fluid Journal • Official Journal of the Fluid Fertilizer Foundation • Winter 2015 • Vol. 23, No. 1, Issue #87 Drs. Terry A. Tindall and Galen Mooso Alfalfa continues to be the world class leader for feed value for North American production agriculture. This is especially true for areas within the inter- mountain West. Acre numbers, while not at historical highs, are still high enough to make these areas either the number 1 or 2 largest cropping sites in each of these states. Forages, including alfalfa, are enjoying some of the greatest economic returns that have been observed for many years. A lot of this is related to changes in population in these areas, diets of international customers, and markets. There continues to be a growth in dairy markets with larger and larger dairy operations at feed yards. All of these contributing factors have pushed the price of alfalfa well beyond expectations from just a few years ago. These changes are bound to get the attention of producers and prompt more questions regarding increased production strategies. The Fluid Fertilizer Foundation continues to have an interest in developing a better understanding of how to more effectively improve nutrient use efficiency (NUE) with the applications of two salt fluids. Proper nutrition Yield of all crops, including alfalfa, will always be dependent on amount and quality of irrigation water in the desert areas of this geography. However, proper nutrition related to available fertility becomes of primary importance. This is especially true for phosphorus (P) use as growers push for high yields and high relative feed value, while also being conscientious about environmental constraints. As Dr. Glenn Shewmaker, Extension Forage Specialist and Professor at the University of Idaho, says, “Phosphorus is the most common fertilizer input for alfalfa across the Western U.S. It is essential for optimum alfalfa production and quality, but may also create concerns for the environment.” Potassium (K) is also a nutrient that is heavily used by rapid-growing alfalfa and in many growing conditions needs to be managed similar to P fertilizer. In the author’s experience, if P and K are both limiting, P should be applied first to resolve the issue and then apply K. In many production fields, although P and K may test adequately in the soil, there may very well be factors that limit the availability to access these primary nutrients in a timely manner to maximize yield and improve alfalfa quality. Objective This unique study explores the potential of addressing in–season application of low salt fluid NPK delivered to alfalfa at the right time within a growing season and between cuttings. Many farmers and researchers focus only on dosage or rate of nutrients applied when other parts of nutrient management criteria should also be explored: namely, timing and form of nutrient delivery. Foliar applications Foliar applications of low salt NPK fertilizers were applied to established irrigated alfalfa during the 2012, 2013, and into the 2014 growing season. Applications were made when the regrowth was about 6 to 8 inches tall. In 2012, applications were made with a commercial sprayer and made between the 2nd and 3rd cuttings. The NPK fluid applications at that time were 3-18-18. Rates of application included a total of 0, 2.5 or 5.0 gallons per acre for each cutting. Irrigation was allowed to be stopped for 24 hours to assure adequate drying on the foliage of the alfalfa. Each treatment was laid out with anticipation of harvest and determining yields. Changes made Applications of foliar nutrients applied in season increased yields during the 2012 season for each of the cuttings. These yield improvements were able to deliver an economic improvement for the forage being used. Kent Frisch, who is the Farm Manager for this area for Simplot, said, “It looks as if these applications are something we should be pursuing. However, the system needs changing for ease of applications.” Therefore, changes were made in 2013 and 2014 to address farmer concerns. MAXIMIZE PROFITS ▼ DOWNLOAD